Macro-Finance ATSM with Bayesian
Main References
Following Ang and Piazzesi (2003),
Following Joslin, Priebsch, and Singleton (2014),
We use Identification of ATSMs > Arbitrage-free Nelson-Siegel ModelIdentification of ATSMs > Arbitrage-free Nelson-Siegel Model from Niu and Zeng (2012):
Then we have
Also,
We summarize up the whole model equations under the above restrictions:
short rate dynamics:
risk-neutral dynamics:
physical dynamics:
market prices of risk:
stochastic discount factor:
Ricatti equations:
risk premiums:
term premium:
Let
When estimating the Affine Term Structure Model (ATSM), the short rate is often excluded because it can be highly volatile and difficult to predict accurately. The short rate, which is the interest rate for an infinitesimally short period, is influenced by a variety of factors, including central bank policies and market conditions. Instead, ATSMs typically focus on longer-term interest rates, which are more stable and provide a clearer picture of the overall term structure. By excluding the short rate, the model can better capture the dynamics of the yield curve and provide more reliable estimates for pricing and risk management.
Now assume that the short rate has measurement errors
Then the measurement equations are
Now following Hamilton and Wu (2012), assume that the short rate, 3-year and 10-year yields are observed without error. Thus we can express these three yields as
Introducing
Then, by ordering the yields so that the last
Thus, the modified state-space is
The parameters we need to estimate are
From